A note on the existence of Nash networks in one-way flow models
针对单向流动网络形成模型，提供了一个更简洁的纳什网络存在性证明，并给出反例说明当链接成本接近但非完全同质时，纳什网络可能不存在。
We study the one-way flow model of network formation with owner-homogeneous link costs and heterogeneous profits. Recently, several proofs of existence of Nash networks are discussed in literature. The proof by Billand et al. (Econ Theory, 2007, forthcoming) is based on a nice and clear idea, but the technical elaboration is tedious and too complex in our opinion. In this note, we provide an alternative and easy accessible proof based on the same idea. Also, we show by means of a counterexample that Nash networks may not exist for games where link costs are heterogeneous, but arbitrarily close to owner-homogeneity.